I'm pretty certain that homosexuality cannot be narrowed down to it simply because people are born that way or that it is a lifestyle choice they make, in fact with people being excited about geneology it could become quite scary if people started to play God and sought to seek out the 'gay gene' un unborn fetuses. I'm honestly not sure what side of the fence to be on when it comes to that. Anyway, it's a lot more complicated than that, ranging from simple curiosity to people seeing it and it becomes an actual fetish for them, or a case of someone being enamored by someone from the same sex.
My question though is why should it matter? Of course Arreat wasn't intending to make it one but I'm sure some people would.